Diaphragm for electrolytic cells



(No Model.)

0. N. WAITE. DIAPHRAGM FOR ELECTROLYTIC BELLS. No. 523,026. PatentedJuly 17, 1894.

witmm UNITED STATES PATENT OFFICE.

CHARLES N. WAITE, OF RUMFORD, MAINE.

DlAPl-IRAGM FOR ELECTROLYTIC CELLS.

SPECIFICATION forming part of Letters Patent No. 523,026, dated July 17,1894.

Application filed August 12, 1893- Serial No. 483,006- (No model.)

To all whom it may concern.-

1 3e it known that 1, CHARLES N. WAITE, a citizen of the United States,residing at Rumford, in the county of Oxford and State of Maine, haveinvented certain new and useful Improvements in Diaphragms forElectrolytic Cells, of which the following is aspecification, referencebeing had therein to the accompany- 1ng drawing.

The diaphragms which heretofore have been employed in electrolyticcells, more particularly those which have been employed in cells usedfor the decomposition of the alkaline chlorides in the manufacture ofchlorine, quickly become injured or destroyed by the action of theproducts of decomposition. In the case of the said production ofchlorine by electrolysis, the chlorine gas which is liberated as aresult of the treatment of the chlorldes aforesaid is highly corrosive,as is well known, and its injurious action upon an ordinary diaphragmsoon becomes apparent. In practice frequent replacing of the diaphragmsis thus rendered necessary. Serious explosions have resulted in caseswhere the injury to the diaphragm has escaped notree, and gas generatedat the negative electrode has been permitted to leak through thediaphragm without the fact being observed or without the place of theleakage being discovered.

The object of my invention is to provide for use in electrolytic cells,and more particularly in those which are employed inthe production ofchlorine or other gaseous sub-- stances, a diaphragm possessing therequisite practical efficiency, and of inexpensive character, whichshall be practically indestructible in use.

I shall proceed to describe my invention with reference to theaccompanying drawing, and afterward shall particularly point out andclearly define the same in the claims at the end of this specification.

The drawing shows in vertical section an electrolytic cell havingmyinvention applied thereto.

The cell itself, as shown in the drawing is .of the general characterwhich is fully exand No. 468,880, granted February 16, 1892, to whichreference may be had.

The present invention, it is to be understood, is not confined to use ina cell of the exact character shown in the drawing and in the saidpatents, and may be applied in connection with other forms of cells,althoughit is best adapted for use in connection with cells of the typewherein the positive electrode is above the negative electrode asin thedrawing and said patents.

At 1 in the drawing is the outer vessel or tank of a cell, containingthe liquid 2 in which the negative electrode 3 is immersed. The form ofnegative electrode shown is one consisting of a number of sheets of wirecloth laid together with a ring 4 preferably of metal applied to theupper surface thereof.

At 5 is shown the bell within which the positive electrode 6 is placedand'by which the said positive electrode is supported. The form ofpositive electrode shown consists ofa metal backing 7 in which are fixeda number of blocks of carbon 8,8. The said positive electrode ispartially immersed in the liquid which is within the bell, the saidliquid'being of somewhat higher levelthan the liquid which is outsidethe bell, as shown.

At 9 is shown a block which is placed underneath one side of thenegative electrode for the purpose of holding the same'and the bell 5,which latter is applied above the negative electrode in manner as shownand as presently will be described, in an inclined or tilted positionwhich facilitates the escape of the gas which is formed at the negativeelectrode.

At 10 is shown an asbestus film, sheet or fabric which lies upon theupper surface of the negative electrode 3. At 11 is shown a ring ofearthenware or other suitable mateof the rim and retaining ring arefitted together so as to produce a tight joint. The sand or othercomminuted matter which is placed within the ring enters and more orless completely fills the interstices of the asbestus film, sheet orfabric and also holds it down in place upon the negative electrode sothat it cannot be floated up or displaced by the gas generated at thesaid negative electrode. This backing or layer of comminuted materialcom bined with the asbestus layer operates to prevent the passage ofhydrogen gas into the anode compartment and this is of the greatestimportance since hydrogen mingling with the chlorine and passing intothe receiving chambers is liable to produce an explosion and is highlydangerous. If the level of the brine be kept higher within the bell thanit is in the tank or containing vessel outside the bell as shown in thedrawing, or if by other means a greater pressure is maintained insidethe bell than exists outside the same, all caustic products of theelectrolysis are prevented from washing up into the positive electrodecompartment, and a higherdegree of efficiency is obtained.

A diaphragm such as herein shown and described is cheap. It possessescomparative indestructibility inasmuch as it is not attacked by chlorineor alkali.

Inasmuch as the chlorine gas sought to be produced forms around thepositive electrode, it is necessary that the electrolytic cell should beconstructed as shown to contain a supply of liquid on the positiveelectrode side of the diaphragm as well as on the negative electrodeside thereof. Also, inasmuch as such gas is freed in considerablequantity and continuously, it is necessary to adopt a construction ofcell in which, as in the drawing, space exists around the positiveelectrode and adjacent to the diaphragm for the free discharge of theliberated gas. The gas makes its exit from the hell 5 through theaperture 13 in' the upper portion thereof, passing into.

the inverted cup 14 which dips into the sealing liquid contained in thegroove 15, the said cup'having a passage 16 in its top for the dischargeof the gas into a suitable conducting pipe applied thereto.

What I claim is 1. The combination with the positive and negativeelectrodes of an electrolytic cell, of a diaphragm having a film, sheetor fabric of indestructible material placed against the negativeelectrode and an adjacent layer of sand or similar comminuted materialresting against said film, sheet or fabric and holding it pressedagainst the said electrode, substantially as described.

2. The combination with the positive and negative electrodes of anelectrolytic cell, of a diaphragm havinga film, sheet or fabric ofasbestus, and a layer of sand, or similar comminuted material overlyingsaid film, sheet or fabric and supported thereby, substantially asdescribed.

3. The combination with the positive and negative electrodes of anelectrolytic cell, of a diaphragm having a film, sheet or fabric ofasbestus, and an overlying layer of sand or similar comminuted materialbearing said film, sheet or fabric against the negative electrode,substantially as described.

4. The combination with the positive and negative electrodes of anelectrolytic cell, of

a diaphragm having a film,sheet or fabric of indestructible material, alayer of sand or similar com minuted material applied thereto, and aretainer for the said comminuted material, holding it in place on thesurface of said film, sheet or fabric, substantially as described.

5. The combination with the positive and negative electrodes of anelectrolytic cell, located one above the other, of a film, sheetorfabric of indestructible material overlying the negative electrode and alayer of sand or similar comminuted material resting upon such film,sheet or fabric, substantially as described. 6. An electrolytic cell foruse-in the production of chlorine, &c., constructed to contain a supplyof liquid on each side of the diaphragm thereof, and with freedischargeabout the positive electrode for the liberated-gas, andprovided with a diaphragm consisting of a layer of sand or comminutedmatter and a film, sheet or fabric of indestructible mate rial whichconstitutes a support for the said layer.

In testimony whereof I affix my signature in presence of two witnesses.

CHARLES N. \VAITE.

Witnesses:

WM. A. MACLEOD, R0121. WALLACE.

